[X86] Try to sync HSW + BDW model class defs to simplify comparisons. NFC.

Broadwell is mainly a die shrink of Haswell, but the model had many of the scheduling classes in different orders, making side-by-side comparisons very difficult.

The InstRW overrides are still quite different, but at least that part of the side-by-side diff is now in the same position.

This was noticed while I was trying to investigate diffs between llvm-mca and other perf analyzers in https://uica.uops.info/ - we used to be able to do diffs between most of the models very easily, but we seem to have lost that simplicity as classes have been altered, models have been refined and other models have rotted.